Transferring semiconductor crystal from a substrate to a resin

ABSTRACT

A semiconductor crystal layer formed by epitaxial growth on a seed crystal substrate is embedded in an insulating material in the condition where the seed crystal substrate is removed, electrodes are provided respectively on a first surface of the semiconductor crystal layer and a second surface of the semiconductor layer opposite to the first surface, and lead-out electrodes connected to the electrodes are led out to the same surface side of the insulating material. The semiconductor crystal layer functions as a semiconductor light-emitting device or a semiconductor electronic device. The insulating material is, for example, a resin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 10/894,771,filed on Jul. 20, 2004, entitled TRANSFERRING SEMICONDUCTOR CRYSTAL FROMA SUBSTRATE TO A RESIN which, in turn, is a Divisional of priorapplication Ser. No. 10/308,914, filed on Dec. 3, 2002, entitledTRANSFERRING SEMICONDUCTOR CRYSTAL FROM A SUBSTRATE TO A RESIN (now U.S.Pat. No. 6,770,960) which, in turn, claims priority to Japaneseapplication No. JP2001-368570 filed Dec. 3, 2001.

BACKGROUND OF THE INVENTION

The present invention relates to an electronic part including as anactive device a semiconductor crystal layer formed by epitaxial growthon a seed crystal substrate, and a method of producing the same.Furthermore, the present invention relates to an image display systemincluding such electronic parts, and a method of manufacturing the same.

In the case of arranging light-emitting devices in a matrix form toassemble an image display system, it has hitherto been practiced toforming the devices directly on a substrate such as in the cases of aliquid crystal display system (LCD) and a plasma display panel (PDP) orto arrange singular LED packages in the case of a light-emitting diodedisplay (LED). For example, in the cases of the image display systemssuch as LCD and PDP, the devices cannot be separated individually, sothat it has been a usual practice to form the devices spaced from eachother by the pixel pitch of the image display system, from the beginningof the manufacture process.

On the other hand, in the case of the LED display, it has been practicedto take out the LED chips after dicing, and connect the LED chipsindividually to external electrodes by bump connection using wirebonding or flip chips, thereby packaging the LED chips. In this case,the LED chips are arranged at the pixel pitch of the image displaysystem before or after the packaging, and the pixel pitch is made to beindependent from the pitch at which the devices are produced.

Since the LED (Light-Emitting Diode) as the light-emitting device isexpensive, it is possible to lower the cost of the image display systemusing the LEDs by producing a multiplicity of LED chips from a singlesheet of wafer. Namely, where the size of the LED chips is several tensof μm square, as contrasted to about 300 μm square in the related art,and the LED chips are connected to manufacture an image display system,it is possible to reduce the price of the image display system.

Meanwhile, among the individual semiconductor devices such as not onlythe light-emitting diode but also, for example, laser diode andtransistor device, there are some devices in which the overall area ofthe device must be not less than several times of the active region (forexample, not less than 0.2 mm square) although the size of the activeregion necessary for operation is on the order of μm. This hampers anenhancement of the actual mounting density of the device or a loweringin the cost of the device.

For example, in the case of high-luminance LED, in account of the factthat a luminance of about several cd is obtained at a chip size of about300 μm square and according to proportional shrinkage, low-luminance LEDwith a luminance of not more than about several mcd might have an activeregion (active layer area) of about 10 μm square. However, according tothe conventional device structure and conventional mounting method, itis difficult to set the overall size of the device closer to the size ofthe active region. In the case of laser diode, the active region is in astripe form with a width of several μm and a length of several hundredsof μm, but in actual mounting, the device size has a width of not lessthan about 200 μm.

Particularly, in the case of a light-emitting diode or a laser diodethat is produced by epitaxial growth of a gallium nitride based crystalon a sapphire substrate, the cathode side (n-type semiconductor layer)and the anode side (p-type semiconductor layer) are sequentiallylaminated. In this case, since the substrate is an insulating body, twoelectrodes must be provided on the growth surface side, so that thedevice size is large due to wire bonding, but the actual area of theactive region (active layer) is rather small. Therefore, internalresistance is high due to flow of current in a lateral direction, andseveral drawbacks such as unfavorable concentration of current aregenerated.

On the other hand, in the case of a light-emitting diode composed of analuminum gallium indium phosphide based crystal grown on a galliumarsenide substrate, electrodes can be provided on both sides of thedevice, but a portion of the light emitted at an active layer isabsorbed by the substrate, so that only an external light emissionefficiency much lower than an intrinsic internal light emissionefficiency can be obtained. In order to solve this problem, a variety ofcontrivances have been practiced, for example, formation of asemiconductor multilayer film (DBR) for light reflection in the inside,formation of a thick window layer, or a transfer onto a transparentsubstrate. These contrivances lead to a rise in cost.

SUMMARY OF THE INVENTION

The present invention has been proposed in consideration of the abovesituations in the related art. Accordingly, it is an object of thepresent invention to provide an electronic part in which the number ofdevices formed from a single sheet of crystalline wafer can be enlargedas compared with the conventional packaged devices, production cost canbe reduced, and it is easy to mount the electronic part in high density,and a method of producing the same. In addition, it is another object ofthe present invention to provide a large-type system, a high-performancesystem, and a system based on integration of a different kinds ofdevices (for example, image display system), which cannot be realizedwith a system based on integration of a multiplicity of devices producedby a monolithic process.

In order to attain the above objects, according to an aspect of thepresent invention, there is provided an electronic part, semiconductorcrystal layer formed by epitxial growth on a seed crystal substrate isembedded in an insulating material in the condition where the seedcrystal substrate is removed, electrodes are provided on a first surfaceof the semiconductor crystal layer and a second surface of thesemiconductor crystal layer opposite to the first surface, and lead-outelectrodes connected to the electrodes are led out to the same surfaceside of the insulating material. A method of producing an electronicpart according to the present invention includes a step of epitaxialgrowth of a semiconductor crystal layer on a seed crystal substrate, astep of embedding the semiconductor crystal layer in an insulatingmaterial and removing the seed crystal substrate, a step of forming anelectrode connected to one surface of the semiconductor crystal layer, astep of transferring the semiconductor crystal layer embedded in theinsulating material onto a support substrate, a step of forming anelectrode connected to the opposite side surface of the semiconductorcrystal layer, and a step of forming lead-out electrodes connected tothe electrodes by leading out the lead-out electrodes to the samesurface side of the insulating material.

In the electronic part having the above-mentioned structure, the regionnecessary for actual mounting and leading-out of electrodes isminimized, and the overall size of the device is suppressed to be small.In addition, for example, in the case of a light-emitting diode, a laserdiode, or the like produced by epitaxial growth of a gallium nitridebased crystal on a sapphire substrate, such problems as an increase ininternal resistance and unfavorable concentration of current aredissolved. In the case of a light-emitting diode including an aluminumgallium indium phosphide based crystal grown on a gallium arsenidesubstrate, high light emission efficiency is realized, and suchcontrivances that may cause a rise in cost are unnecessary.

On the other hand, according to another aspect of the present invention,there is provided an image display system including electronic partsincluding light-emitting devices arranged in a matrix form on asubstrate, each of the electronic parts constituting a pixel. Asemiconductor crystal layer functioning as a light-emitting deviceproduced by epitaxial growth on a seed crystal substrate is embedded inan insulating material in the condition where the seed crystal substrateis removed, electrodes are provided respectively on a first surface ofthe semiconductor crystal layer and a second surface of thesemiconductor crystal layer opposite to the first surface, each of theelectronic parts is covered with an insulating layer, and lead-outelectrodes each connected to each of the electrodes of the semiconductorcrystal layer contained in the electronic part are led out to the faceside of the insulating layer. In addition, a method of manufacturing animage display system according to the present invention resides in amethod of manufacturing an image display system including electronicparts including light-emitting devices arranged in a matrix form on asubstrate, each of the electronic parts constituting a pixel. The methodincludes a step of epitaxially growing semiconductor crystal layers forfunctioning as light-emitting devices on a seed crystal substrate, afirst transfer step of transferring the semiconductor crystal layersonto a first temporary holding member in the condition where thesemiconductor crystal layers are spaced wider apart than they have beenarranged on the seed crystal substrate and holding the semiconductorcrystal layers by embedding the semiconductor crystal layers in aninsulating material, a step of forming electrodes connected to one sideof the semiconductor crystal layers, a second transfer step oftransferring the semiconductor crystal layers embedded in the insulatingmaterial onto a second temporary holding member, a step of formingelectrodes connected to the opposite side of the semiconductor crystallayers, a step of cutting the insulating material with the semiconductorcrystal layers embedded therein to separate individual electronic parts,a third transfer step of transferring the electronic parts held on thesecond temporary holding member onto a second substrate while spacingthe electronic parts further wider apart, a step of providing aninsulating layer so as to cover each of the electronic parts, and a stepof leading out, to the face side of the insulating layer, lead-outelectrodes connected to the electrodes of the semiconductor crystallayers contained in the electronic parts.

According to the image display system and the method of manufacturingthe same, the light-emitting devices rearranged in the spaced-apartcondition are arranged in a matrix form to constitute an image displayportion. Therefore, the light-emitting devices produced by fineprocessing with a dense condition, namely, with a high degree ofintegration can be efficiently rearranged in the spaced-apart condition,and productivity is largely enhanced. In addition, the light-emittingdevices converted into electronic parts can be actually mounted in ahigh density, and wiring therefor can be easily formed.

According to the present invention, it is possible to provide anelectronic part such that the number of devices produced from a singlesheet of crystal wafer can be enlarged as compared with the conventionalpackaged devices, the production cost can be reduced, and actualmounting in a high density is easy. In addition, it is possible toprovide a large-type system, a high-performance system, and a systembased on integration of different kinds of devices (for example, animage display system), which cannot be realized with a system based onintegration of a multiplicity of devices produced by a monolithicprocess. On the other hand, according to the image display system andthe method of manufacturing the same according to the present invention,while the above-mentioned merits are maintained, the light-emittingdevices produced by fine processing with a dense condition, namely, witha high degree of integration can be efficiently rearranged with thespaced-apart condition. Therefore, an image display system with highaccuracy can be produced with high productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of the invention will be seen by reference tothe description, taken in connection with the accompanying drawing, inwhich:

FIG. 1 is a general sectional view showing one example in which thepresent invention is applied to a gallium nitride based light-emittingdiode;

FIG. 2 is a general sectional view showing one example in which acathode take-out electrode is a transparent electrode;

FIG. 3 is a general sectional view showing one example in which light isoutputted from the side of an electrode pad;

FIG. 4 is a general sectional view showing one example in which a sidesurface of a light-emitting diode is composed of a {1-101} crystal plane(S plane);

FIG. 5 is a general perspective view showing another example in which aside surface of a light-emitting diode is composed of an S plane;

FIG. 6 is a general sectional view showing one example in which thepresent invention is applied to an aluminum gallium indium phosphidebased light-emitting diode device;

FIG. 7 is a general sectional view showing one example in which acathode take-out electrode is a transparent electrode;

FIG. 8 is a general perspective view showing one example in which thepresent invention is applied to a gallium nitride based laser diode;

FIG. 9 is a general perspective view showing one example in which thepresent invention is applied to an aluminum gallium indium phosphidebased laser diode device;

FIG. 10 is a general sectional view showing one example in which thepresent invention is applied to a field effect type transistor;

FIG. 11 is a general plan view showing one example in which the presentinvention is applied to a field effect type transistor;

FIG. 12 is a general sectional view showing one example in which a resinlayer is provided covering an electrode on the back side;

FIGS. 13A to 13D show schematic diagrams illustrating a method ofarranging devices;

FIG. 14 is a general perspective view of a resin molded chip;

FIG. 15 is a general plan view of the resin molded chip;

FIGS. 16A and 16B show views showing one example of a light-emittingdevice, in which FIG. 16A is a sectional view, and FIG. 16B is a planview;

FIG. 17 is a general sectional view showing a step of bonding a firsttemporary holding member;

FIG. 18 is a general sectional view showing a step of curing aUV-curable adhesive;

FIG. 19 is a general sectional view showing a laser ablation step;

FIG. 20 is a general sectional view showing a step of separating a firstsubstrate;

FIG. 21 is a general sectional view showing a Ga removing step;

FIG. 22 is a general sectional view showing a step of forming a deviceseparation groove;

FIG. 23 is a general sectional view showing a step of bonding a secondtemporary holding member;

FIG. 24 is a general sectional view showing a selective laser ablationand UV exposure step;

FIG. 25 is a general sectional view showing a step of selectivelyseparating light-emitting diodes;

FIG. 26 is a general sectional view showing a step of embedding by useof a resin;

FIG. 27 is a general sectional view showing a step of reducing thethickness of a resin layer;

FIG. 28 is a general sectional view showing a via forming step;

FIG. 29 is a general sectional view showing a step of forming anelectrode pad on the anode side;

FIG. 30 is a general sectional view showing a laser ablation step;

FIG. 31 is a general sectional view showing a step of separating thesecond temporary holding member;

FIG. 32 is a general sectional view showing a step of exposing a contactsemiconductor layer;

FIG. 33 is a general sectional view showing a step of forming anelectrode pad on the side of a cathode;

FIG. 34 is a general sectional view showing a laser dicing step;

FIG. 35 is a general sectional view showing a step of selective pick-upby a suction device;

FIG. 36 is a general sectional view showing a step of transfer onto asecond substrate;

FIG. 37 is a general sectional view showing another step of transfer oflight-emitting diodes;

FIG. 38 is a general sectional view showing a step of forming aninsulating layer;

FIG. 39 is a general sectional view showing a wiring forming step; and

FIG. 40 is a general sectional view showing a step of forming aprotective layer and a black mask.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, an electronic part and a method of producing an electronic part byapplication of the present invention, and further, an image displaysystem and a method of manufacturing an image display system byapplication thereof will be described in detail below referring to thedrawings.

FIG. 1 shows an example in which the present invention is applied to agallium nitride based light-emitting diode. The light-emitting diode iscomposed of an n-GaN window layer 1 epitaxially grown on a sapphiresubstrate, a GaInN active layer 2, and a p-GaN clad layer 3. Thesesemiconductor crystal layers are embedded in a resin layer 4. The sizeof the semiconductor crystal layer is, for example, not more than 100 μmsquare, and the size of the resin layer 4 is, for example, not less than150 μm square. Of the GaInN active layer 2, the region surrounded by thebroken line is an active region, and a light output in the direction ofthe arrow is obtained.

The n-GaN window layer 1 is exposed from the resin layer 4 to theoutside, and a cathode contact electrode 5 is provided in contact withthe surface fronting on the outside. In addition, a cathode take-outelectrode 6 is provided in the state of being connected to the cathodecontact electrode 5. A lead-out electrode 8 led out to an upper surface4 a in the figure of the resin layer 4 through a via 7 penetratingthrough the resin layer 4 is provided in the state of being connected tothe cathode take-out electrode 6. On the other hand, an anode contactelectrode 9 is provided in the state of being connected to the surfaceon the opposite side of the semiconductor crystal layer functioning as alight-emitting diode, namely, to the surface of the p-GaN clad layer 3,and again, an anode take-out electrode 11 led out to the upper surface 4a of the resin layer 4 through a via 10 is provided.

In this example, a semiconductor device having a size of not more than100 μm square is embedded in the resin having a size of not less than150 μm square, the number of devices produced from a single sheet ofwafer is greater as compared with that in the case of conventional typedevices, and it is enabled to achieve a high light emission efficiencyand a mechanical mounting in a high density. Where the cathode take-outelectrode 6 is formed of a transparent electrode material as atransparent electrode, take-out of light is not hindered without formingthe cathode take-out electrode 6 as a larger pattern to form anelectrode pattern with high accuracy as shown in FIG. 2.

While a structure in which light is outputted downwards in the figure,namely, from the surface on the opposite side of the surface whereelectrode pads for connection (a lead-out electrode 8 and an anodetake-out electrode 11) are formed is adopted in the above example, astructure in which light is outputted from the surface where theelectrode pads are formed may also be adopted. FIG. 3 shows an examplein which the latter structure is adopted. In this example, the basicstructure is the same as that in FIG. 1 above, but the light isoutputted in the direction of the arrow (upwards in the figure) as shownin the figure.

FIG. 4 shows an example in which side surfaces of a light-emitting diode(namely, a semiconductor crystal layer) are each constituted of a{1-101} crystal plane (S plane). Though the basic structure is the sameas that in FIG. 1, the side surfaces of the semiconductor crystal layercomposing of the n-GaN window layer 1, the GaInN active layer 2, and thep-GaN clad layer 3 are slant surfaces. With the side surfaces of thesemiconductor crystal layer being slant surfaces (S planes), the lightdischarged in lateral directions in the case of the device with thevertical side surfaces is radiated forwards after being reflected backdue to internal reflection, and the efficiency of take-out of lighttoward the front side (in the direction of the arrow) is enhanced.Therefore, as a result, the luminance as viewed from the front side isenhanced, in the case of operation with a fixed electric power.

FIG. 5 shows an example in which the structure shown in FIG. 4 isfurther developed. In this example, side surfaces of a light-emittingdiode (semiconductor crystal layer) are each composed of an S plane. Inconcrete, a growth inhibitive mask 1 a is provided on the surface of ann-GaN window layer 1, and by the crystal growth inhibitive effect of themask la, an n-GaN window layer 1 b, a GaInN active layer 2, and a p-GaNclad layer 3 are epitaxially grown thereon in a conical shape or apolygonal pyramid shape. Where such a structure is adopted, the lightdischarged in lateral directions in the case of a device with verticalside surfaces is radiated forwards after being reflected back due tointernal reflection, and the luminance as viewed from the front side isenhanced. Simultaneously, the active layer formed on the S plane hasfewer crystal defects as compared with a conventional C plane (0001), sothat internal light emission efficiency is high, and synthetically, afurther enhancement of luminance is obtained.

FIG. 6 shows an example in which the present invention is applied to analuminum gallium indium phosphide based light-emitting diode device. Thebasic structure is the same as that shown in FIG. 1 above, and only theconstitution of the device differs. In concrete, the aluminum galliumindium phosphide based light-emitting diode device is composed of ann-AlGaInP window layer 21 formed by epitaxial growth on a seed crystalsubstrate constituting of gallium arsenide or indium phosphide, anAlGaNiP active layer 22, and a p-AlGaInP clad layer 23, as shown in FIG.6. The aluminum gallium indium phosphide based light-emitting diodedevice is embedded in a resin layer 24; of the AlGaInP active layer 22,the region surrounded by the broken line is an active region, and alight output is obtained in the direction of the arrow.

The n-AlGaInP window layer 21 is exposed from the resin layer 24 tofront on the outside, and a cathode contact electrode 25 is provided incontact with the surface fronting on the outside. In addition, a cathodetake-out electrode 26 is provided in the state of being connected to thecathode contact electrode 25. A lead-out electrode 28 led out to anupper surface 24 a in the figure of the resin layer 24 through a via 27penetrating through the resin layer 24 is provided in the state of beingconnected to the cathode take-out electrode 26. On the other hand, ananode contact electrode 29 is provided in contact with the surface onthe opposite side of the semiconductor crystal layer functioning as alight-emitting diode, namely, with the surface of the p-AlGaInP cladlayer 23, and again, an anode take-out electrode 31 led out to the uppersurface 24 a of the resin layer 24 through a via 30 is provided. In thisexample, the semiconductor device having a size of not more than 100 μmsquare is embedded in a resin having a size of not less than 150 μmsquare, the number of devices produced from a single sheet of wafer isgreater as compared with the conventional type devices, and a high lightemission efficiency and a mechanical mounting in a high density areenabled. Where the cathode take-out electrode 26 is formed of atransparent electrode material as a transparent electrode, take-out oflight is not hindered without forming the cathode take-out electrode 26as a large pattern to form an electrode pattern with high accuracy asshown in FIG. 7.

FIG. 8 shows an example in which the present invention is applied to agallium nitride based laser diode. The laser diode is composed of ann-GaN window layer 41 epitaxially grown on a sapphire substrate, a GaInNactive layer 42, and a p-GaN clad layer 43, and these semiconductorcrystal layers are embedded in a resin layer 44. The p-GaN clad layer 43has a rib portion 43 a with a predetermined width (for example, 3 μm inwidth); corresponding to this, of the GaInN active layer 42, the regionsurrounded by the broken line functions as an active region, and a lightoutput is obtained in the direction of the arrow.

The n-GaN window layer 41 is exposed from the resin layer 44 to front onthe outside, and a cathode contact electrode 45 is provided in contactwith the surface fronting on the outside. In addition, a cathodetake-out electrode 46 is provided in the state of being connected to thecathode contact electrode 45. A lead-out electrode 48 led out to anupper surface 44 a in the figure of the resin layer 44 through a via 47penetrating through the resin layer 44 is provided in the state of beingconnected to the cathode take-out electrode 46. On the other hand, ananode contact electrode 49 is provided in contact with the surface onthe opposite side of the semiconductor crystal layer functioning as alaser diode, namely, with the surface of the rib portion 43a of thep-GaN clad layer 43, and again, an anode take-out electrode 51 led outto the upper surface 44 a of the resin layer 44 through a via 50 isprovided.

In the above example, the width of the active region is about 3 μm, sothat the width of the semiconductor crystal layer to be diced can bereduced to about 10 μm. In addition, by disposing this package directlyon a heat sink, it is possible to reduce thermal resistance as comparedwith the case where the sapphire substrate is left, and to restrain alowering in the performance due to heat generation. Further, by cleavageafter separation from the sapphire substrate, the resulting flat endface becomes a mirror surface with high quality for constituting anoptical resonator, and a laser device with high performance can beobtained in a high yield.

FIG. 9 shows an example in which the present invention is applied to analuminum gallium indium phosphide based laser diode device. The basicstructure is the same as that shown in FIG. 8 above, and only theconstitution of the device differs. In concrete, the aluminum galliumindium phosphide based laser diode device is composed of an n-AlGaInPwindow layer 61 formed by epitaxial growth on a seed crystal substrateconstituting of gallium arsenide or indium phosphide, an AlGaInP activelayer 62, and a p-AlGaInP clad layer 63, as shown in FIG. 8. Thealuminum gallium indium phosphide based laser diode device is embeddedin a resin layer 64, and the p-AlGaInP clad layer 63 has a rib portion63 a with a predetermined width (for example, 3 μm in width);corresponding to this, of the AlGaInP active layer 62, the regionsurrounded by the broken line functions as an active region, and a lightoutput is obtained in the direction of the arrow.

The n-AlGaInP window layer 61 is exposed from the resin layer 64 tofront on the outside, and a cathode contact electrode 65 is provided incontact with the surface fronting on the outside. In addition, a cathodetake-out electrode 66 is provided in the state of being connected to thecathode contact electrode 65. A lead-out electrode 68 led out to anupper surface 64 a in the figure of the resin layer 64 through a via 67penetrating through the resin layer 64 is provided in the state of beingconnected to the cathode take-out electrode 66. On the other hand, ananode contact electrode 69 is provided in contact with the surface onthe opposite side of the semiconductor crystal layer functioning as alight-emitting diode, and again, an anode take-out electrode 71 led outto the upper surface 64 a of the resin layer 64 through a via 70 isprovided.

Also in the above example, the width of the active region is about 3 μm,so that the width of the semiconductor crystal layer to be diced can bereduced to about 10 μm. In addition, by disposing this package directlyon a heat sink, it is possible to reduce thermal resistance as comparedwith the case where the sapphire substrate is left, and to restrain alowering in the performance due to heat generation. Further, where awindow structure is formed in the vicinity of an end face so as toenhance the output, cleavage after removal of the substrate makes itpossible to control the position of the end face with high accuracy, andto obtain a device with stable performance in a high yield.

FIGS. 10 and 11 show an example in which the present invention isapplied to a field effect type transistor (FET). The field effect typetransistor is produced by providing a source electrode 82, a drainelectrode 83, a gate electrode 84, and the like on a semiconductorcrystal 81 constituting of Si, GaAs, or the like. The semiconductorcrystal 81 provided with these components is embedded in a resin layer85, and a bottom surface 81 a thereof is exposed from the resin layer 85to front on the outside. In addition, take-out electrodes 89, 90, and 91are led out from the source electrode 82, the drain electrode 83, andthe gate electrode 84 to a surface (the upper surface in the figure) ofthe resin layer 85 through vias 86, 87, and 88. A body take-outelectrode 92 is connected to the bottom surface 81 a of thesemiconductor crystal 81 and is connected to a take-out electrode 94 ledout to a surface (the upper surface in the figure) of the resin layer85, which is in the same manner as the other take-out electrodes 89, 90,and 91, through a via 93.

For example, in the cases of a switching transistor for pixels in aliquid crystal display system or a driving transistor for a minutelight-emitting diode with an operating current in a microampere region,the size of the active region may be not more than about 10 μm square,and the amount of semiconductor wafer used can be suppressed byminimizing the region necessary for actual mounting and take-out ofelectrodes. Therefore, an image display system substantially usingseveral hundreds of thousands of devices per system can be realized by ahybrid system, and it is possible to achieve an increase in area, whichcannot be achieved by a monolithic system. Besides, also in the sizeregion that is possible by the monolithic system utilizing an amorphoussemiconductor or a polycrystalline semiconductor, a system with highperformance can be obtained by actually mounting single-crystalsemiconductor devices by this method.

Meanwhile, in each of the electronic parts described above, it is alsopossible to provide the resin layer covering the electrode on the backside, to facilitate the release or the like from, for example, atemporary holding substrate or the like, and to convert the device intothe so-called chip component part, which is easy to deal with. FIG. 12shows an example in which, in the gallium nitride based light-emittingdiode shown in FIG. 1, a resin layer 101 formed of polyimide or the likeis provided covering the cathode take-out electrode 6 formed on theresin layer 4, to convert the device into a chip component part. Such astructure can be easily formed through inversion, transfer, and the likesteps, and is a novel structure in which a both-side take-out structureon the resin layer is provided.

Next, description will be made by taking as an example an image displaysystem obtained by application of rearrangement of devices by atwo-stage enlarged transfer method. First, basic constitutions of adevice arranging method based on the two-stage enlarged transfer methodand a method of manufacturing an image display system will be described.The device arranging method based on the two-stage enlarged transfermethod and the method of manufacturing the image display system includea two-stage enlarged transfer in which devices formed on a firstsubstrate in a high degree of integration are transferred onto atemporary holding member so that the devices are spaced wider apart thanthey have been arranged on the first substrate, and then the devicesheld on the temporary holding member are transferred onto a secondsubstrate while being spaced further wider apart. While the transfer isconducted in two stages in this example, the transfer may be conductedin three or more stages according to the degree of enlargement of thedevices.

FIGS. 13A to 13D show schematic diagrams respectively illustrating basicsteps of the two-stage enlarged transfer method. First, devices 112 suchas, for example, light-emitting devices are formed densely on a firstsubstrate 110 shown in FIG. 13A. With the devices formed densely, thenumber of the devices produced per substrate can be enlarged, andproduction cost can be lowered. The first substrate 110 is a substrateon which various devices can be produced such as, for example, asemiconductor wafer, a glass substrate, a quartz glass substrate, asapphire substrate, and a plastic substrate. The devices 112 may bethose formed directly on the first substrate 110, or may be formed onanother substrate and arranged on the first substrate 110.

Next, as shown in FIG. 13B, the devices 112 are transferred from thefirst substrate 110 onto a temporary holding member 111, and are held onthe temporary holding member 111. At this time, simultaneously, coveringof the surroundings of the devices 112 with a resin is conducted on thebasis of each of the devices 112. The covering of the surroundings ofthe devices with the resin is conducted for facilitating formation ofelectrode pads, for facilitating the treating of the devices in atransfer step, and the like purposes. The adjacent devices 112 aresubjected to selective separation by, for example, transfers between aplurality of temporary holding members, whereby finally the devices 112are spaced apart on the temporary holding member, and are arranged in amatrix form as shown in the figure. Namely, while the devices 112 are sotransferred that they are spaced wider apart in an x-direction, thedevices 112 are so transferred that they are spaced wider apart also ina y-direction perpendicular to the x-direction. The interval to whichthe devices 112 are spaced wider apart is not particularly limited, andmay for example be an interval determined by taking into account theformation of a resin layer or formation of electrode pads in thesubsequent steps.

After such a first transfer step, the devices 112 present on thetemporary holding member 111 are spaced apart, and formation ofelectrode pads is conducted on the basis of each of the devices 112, asshown in FIG. 13C. The formation of the electrode pads is conducted witha comparatively large pad size so that failure or defects in wiringwould not occur in the final wiring, which is performed after thesubsequent second transfer step, as will be described later. Theelectrode pads are not shown in FIG. 13C. The electrode pads are formedfor each of the devices 112 fixed by the resin 113, whereby resin-moldedchips 114 are formed. While the device 112 is located at a roughlycentral position of the resin-molded chip 114 in plan view, the device112 may be present at a position closer to one side or one corner of theresin-molded chip 114.

Next, as shown in FIG. 13D, the second transfer step is conducted. Inthis second transfer step, the devices 112 arranged in the matrix formon the temporary holding member 111 are transferred onto a secondsubstrate 115 so that they are spaced further wider apart on the basisof the resin-molded chips 114. Also in the second transfer step, theadjacent devices 112 are spaced apart on the basis of the resin-moldedchips 114, and are arranged in a matrix form as shown in the figure.Namely, while the devices 112 are so transferred as to be spaced widerapart in the x-direction, the devices 112 are so transferred as to bespaced wider apart also in the y-direction perpendicular to thex-direction. Where the positions of the devices arranged by the secondtransfer step correspond to pixels of the final product such as an imagedisplay system, roughly an integer times of the initial pitch of thedevices 112 will be the pitch of the devices 112 arranged by the secondtransfer step. Here, the value E of the roughly integer times isexpressed by the formula E=n×m, where n is the ratio of enlargement ofspaced pitch on the transfer from the first substrate 110 onto thetemporary holding member 111, and m is the ratio of enlargement ofspaced pitch on the transfer from the temporary holding member 111 ontothe second substrate 115.

Wiring is applied to each of the devices 112 spaced apart on the basisof the resin-molded chips 114 on the second substrate 115. At this time,wiring is conducted while restraining as much as possible failure ordefects in connection, by utilizing the electrode pads or the likepreliminarily provided. For example, where the devices 112 arelight-emitting devices such as light-emitting diodes, the wiringincludes wirings to p-electrodes and n-electrodes; where the devices 112are liquid crystal control devices, the wiring includes at least wiringsfor selection signal lines, voltage lines, orientation electrode films,and the like.

In the two-stage enlarged transfer method illustrated in FIG. 13,formation of the electrode pads and the like can be conducted byutilizing the spaces between the devices after the first transfer, andthe wiring is conducted after the second transfer; in this case, thewiring is conducted while restraining as much as possible failure ordefects in connection, by utilizing the electrode pads and the likepreliminarily provided. Therefore, it is possible to enhance the yieldof the image display system. In addition, in the two-stage enlargedtransfer method in this example, the steps of spacing the devices widerapart are two steps, and by performing a plurality of steps of enlargedtransfer for spacing the devices wider apart, the number of transfers isreduced in practice. Namely, for example, where the ratio of enlargementof spaced pitch on the transfer from the first substrate 110, 110 a ontothe temporary holding member 111, 111 a is 2 (n=2) and the ratio ofenlargement of spaced pitch on the transfer from the temporary holdingmember 111, 111 a onto the second substrate 115 is 2 (m=2), if thetransfer to the enlarged range is to be performed by a single transfer,the final enlargement ratio is 2×2=4 times, and the square of 4 is 16,so that it is necessary to perform the transfer, namely, alignment ofthe first substrate, 16 times. On the other hand, according to thetwo-stage enlarged transfer method in this example, the number of timesof alignment required is only 8 times in total, which is a simple sum ofthe 4 times, which is the square of the enlargement ratio of 2 in thefirst transfer step and the 4 times, which is the square of theenlargement ratio of 2 in the second transfer step. Namely, since(n+m)²=n²+2 nm+m², in the case of intending the same enlargement ratioof transfer, it is always possible to reduce the number of times oftransfer by 2 nm times according to the two-stage enlarged transfermethod. Therefore, the production process is reduced in time and cost byamounts corresponding to this number of times of alignment, which isparticularly profitable where the ratio of enlargement of pitch isgreat.

While the device 112 is, for example, a light-emitting diode in thetwo-stage enlarged transfer method shown in FIG. 13, this is notlimitative, and the device may be any one selected from other devices,for example, a liquid crystal control device, a photo-electricconversion device, a piezoelectric device, a thin film transistordevice, a thin film diode device, a resistance device, a switchingdevice, a minute magnetic device, and a minute optical device, or a partthereof or a combination thereof.

In the second transfer step described above, the light-emitting devicesare dealt with as resin-molded chips and are respectively transferredfrom the temporary holding member onto the second substrate. Theresin-molded chip will be described referring to FIGS. 14 and 15. Theresin-molded chip 120 is obtained by fixing the surroundings of thedevice 121 arranged in a spaced-apart condition with the resin 122, andthe resin-molded chip 120 can be used at the time of transferring thedevice 121 from the temporary holding member onto the second substrate.The resin-molded chip 120 is roughly flat plate shaped, and majorsurfaces thereof are each roughly square. The shape of the resin-moldedchip 120 is a shape formed by fixing with the resin 122; concretely, theshape is obtained by applying an uncured resin to the whole surface soas to contain each device 121, and after curing of the resin, edgeportions are cut by dicing or the like.

Electrode pads 123 and 124 are provided respectively on the face sideand the back side of the roughly flat plate shaped resin 122. Theelectrode pads 123 and 124 are each formed by forming a conductive layersuch as a metallic layer and a polycrystalline silicon layer, whichconstitute the material of the electrode pads 123, 124 on the wholesurface, and then patterning the conductive layer into a requiredelectrode shape by photolithography technology. The electrode pads 123and 124 are so formed as to be connected respectively to the p-electrodeand an n-electrode of the device 121, which is the light-emittingdevice, and if necessary, the resin 122 is provided with via holes orthe like.

While the electrode pads 123 and 124 are provided respectively on theface side and the back side of the resin-molded chip 120, they may beprovided on the same side of the resin-molded chip 120. In addition,since three electrodes for source, gate, and drain are present in thecase of a thin film transistor, for example, three or more electrodepads may be provided. The arrangement in which the positions of theelectrode pads 123 and 124 are staggered from each other in plan view isfor ensuring that contacts taken from the upper side at the time offinal formation of wirings will not overlap with each other. The shapeof the electrode pads 123 and 124 is not limited to square, and may beother shape.

By constituting such a resin-molded chip 120, the surroundings of thedevice 121 can be covered with the resin 122, which is planarized,whereby the electrode pads 123 and 124 can be formed with high accuracy,and the electrode pads 123 and 124 can be extended to wider areas ascompared with the device 121, whereby treating of the device 121 isfacilitated in the case of conducting transfer in the subsequent secondtransfer step by use of a suction jig. As will be described later, thefinal wiring is conducted after the subsequent second transfer step, sothat failure or defects in wiring can be prevented by conducting thewiring by utilizing the electrode pads 123 and 124 whose size iscomparatively large.

Next, FIGS. 16A and 16B show the structure of a light-emitting device asan example of a device used in the two-stage enlarged transfer method inthis example. FIG. 16A is a sectional view of the device, and FIG. 16Bis a plan view of the same. The light-emitting device is a GaN basedlight-emitting diode and is crystally grown on, for example, a sapphiresubstrate. In such a GaN based light-emitting diode, laser ablation isgenerated by irradiation with laser transmitted through the substrate,and film exfoliation is generated at the interface between the sapphiresubstrate and the GaN based grown layer in accordance with on thephenomenon in which nitrogen in GaN is gasified.

First, as to the structure, a hexagonal base pyramid shaped GaN layer132 selectively grown on a ground growth layer 131 forming of a GaNbased semiconductor layer is provided. An insulating film not shown ispresent on the ground growth layer 131, and the hexagonal base pyramidshaped GaN layer 132 is formed on an opened portion of the insulatingfilm by an MOCVD method or the like. The GaN layer 132 is a pyramidshaped grown layer covered with S planes (1-101 planes) where theprimary surface of the sapphire substrate used for growth is a C planeand is a region doped with silicon. The portions of the inclined Splanes of the GaN layer 132 function as clads with a double-heterostructure. An InGaN layer 133, which is an active layer is provided soas to cover the inclined S planes of the GaN layer 132, and amagnesium-doped GaN layer 134 is provided on the outside thereof. Themagnesium-doped GaN layer 134 also functions as a clad.

Such a light-emitting diode is provided with a p-electrode 135 and ann-electrode 136. The p-electrode 135 is formed by vapor deposition of ametallic material such as Ni/Pt/Au or Ni(Pd)/Pt/Au on themagnesium-doped GaN layer 134. The n-electrode 136 is formed by vapordeposition of a metallic material such as Ti/Al/Pt/Au on the openedportion of the insulating film (not shown) described above. In the casewhere the n-electrode is taken out from the back side of the groundgrowth layer 131, formation of the n-electrode 136 is not needed on theface side of the ground growth layer 131.

The GaN based light-emitting diode having such a structure is a devicecapable also of emitting blue light, and particularly, can be releasedfrom the sapphire substrate comparatively easily by laser ablation;selective release can be realized by selective irradiation with laserbeam. The GaN based light-emitting diode may have a structure in whichthe active layer is provided in a flat plate shape or a belt shape, andmay have a pyramidal structure in which a C plane is provided at a topend portion. In addition, other nitride based light-emitting diodes andcompound semiconductor devices may also be adopted.

Next, a concrete technique of manufacturing an image display system byapplying the light-emitting device arranging method shown in FIG. 13will be described. The light-emitting device uses a GaN basedlight-emitting diode shown in FIG. 16. First, as shown in FIG. 17, aplurality of light-emitting diodes 142 are provided in a dense conditionon a primary surface of a first substrate 141. The size of thelight-emitting diodes 142 can be minute, for example, about 20 μmsquare. As a material for constituting the first substrate 141, amaterial having a high transmittance for the wavelength of the laser,which the light-emitting diodes 142 are irradiated such as a sapphiresubstrate, is used. The light-emitting diodes 142 are each provided withup to the p-electrode, but the final wiring is not yet conducted;grooves 142 g for separation between the devices are provided, and theindividual light-emitting diodes 142 can be separated. Formation of thegrooves 142 g is conducted by reactive ion etching, for example.

Next, the light-emitting diodes 142 on the first substrate 141 aretransferred onto a first temporary holding member 143. Here, as anexample of the first temporary holding member 143, there can be used aglass substrate, a quartz glass substrate, a plastic substrate, and thelike; in this example, a quartz glass substrate is used. In addition, arelease layer 144 functioning as a mold release layer is provided on thesurface of the first temporary holding member 143. For the release layer144, there can be used a fluoro coat, a silicone resin, a water-solubleadhesive (for example, polyvinyl alcohol [PVA]), polyimide, and thelike; here, polyimide is used.

At the time of transfer, as shown in FIG. 17, an adhesive (for example,a UV-curable type adhesive) 145 is applied onto the first substrate 141in such an amount as to cover the light-emitting diodes 142, and thefirst temporary holding member 143 is laid thereon so as to be supportedby the light-emitting diodes 142. In this condition, the adhesive 145 isirradiated with ultraviolet rays (UV) from the back side of the firsttemporary holding member 143 as shown in FIG. 18, thereby curing theadhesive 145. The first temporary holding member 143 is a quartz glasssubstrate, so that the ultraviolet rays are transmitted therethrough, torapidly cure the adhesive 145.

At this time, the first temporary holding member 143 is supported by thelight-emitting diodes 142, so that the spacing between the firstsubstrate 141 and the first temporary holding member 143 is determinedby the height of the light-emitting diodes 142. When the adhesive 145 iscured under the condition where the first temporary holding member 143is so laminated as to be supported by the light-emitting diodes 142 asshown in FIG. 18, the thickness t of the adhesive 145 is restricted bythe spacing between the first substrate 141 and the first temporaryholding member 143. Therefore, the thickness of t of the adhesive 145 isrestricted by the height of the light-emitting diodes 142. Namely, thelight-emitting diodes 142 on the first substrate 141 play the role ofspacer, whereby the adhesive layer with a fixed thickness is formedbetween the first substrate 141 and the first temporary holding member143. Thus, in the above-described method, the thickness of the adhesivelayer is determined by the height of the light-emitting diodes 142, sothat an adhesive layer with a fixed thickness can be formed withoutsevere control of pressure.

After the curing of the adhesive 145, as shown in FIG. 19, thelight-emitting diodes 142 are irradiated with laser from the back sideof the first substrate 141, and the light-emitting diodes 142 arereleased from the first substrate 141 by utilizing laser ablation. Sincethe GaN based light-emitting diode 142 is decomposed into metallic Gaand nitrogen at the interface between itself and sapphire, thelight-emitting diodes 142 can be released comparatively easily. As thelaser for irradiation, excimer laser, higher harmonic YAG laser may beused. By the release utilizing the laser ablation, the light-emittingdiodes 142 are separated at the interface between themselves and thefirst substrate 141, and are transferred onto the temporary holdingmember 143 in the state of being embedded in the adhesive 145.

FIG. 20 shows the condition where the first substrate 141 has beenremoved by the above-mentioned release. At this time, the GaN basedlight-emitting diodes have been released from the first substrate 141composing of the sapphire substrate by the laser, and Ga 146 has beendeposited at the release surface, so that the deposited Ga must beetched. In view of this, wet etching is conducted by use of an aqueousNaOH solution or diluted nitric acid, whereby Ga 146 is removed, asshown in FIG. 21. Further, cleaning of the surface is conducted by useof oxygen plasma (O₂ plasma), then, as shown in FIG. 22, the adhesive145 is cut along the dicing grooves 147 by dicing, and dicing on thebasis of each light-emitting diode 142 is conducted, followed byselective separation of the light-emitting diodes 142. The dicingprocess may be conducted by conventional blade dicing; where narrow cutswith a width of not more than 20 μm is necessary, laser processing byuse of the above-mentioned laser is conducted. The width of the cutsdepends on the size of the light-emitting diode 142 covered with theadhesive 145 in the pixel of the image display system; as one example,grooves are processed by excimer laser, whereby the shape of the chip isformed.

For selectively separating the light-emitting diodes 142, first, asshown in FIG. 23, a UV adhesive 148 is applied onto the cleanedlight-emitting diodes 142, and a second temporary holding member 149 islaid thereon. As the second temporary holding member 149, there can beused a glass substrate, a quartz glass substrate, a plastic substrate inthe same manner as in the case of the first temporary holding member143; in this example, a quartz glass substrate is used. A release layer150 formed of polyimide or the like is preliminarily provided also onthe face side of the second temporary holding member 149.

Next, as shown in FIG. 24, laser is radiated from the back side of thefirst temporary holding member 143 at only the positions correspondingto the light-emitting diodes 142 a being the objects of transfer, andthe light-emitting diodes 142 a are released from the first temporaryholding member 143 by laser ablation. Simultaneously, UV exposure isconducted by radiating ultraviolet rays (UV) from the back side of thesecond temporary holding member 149 at the positions corresponding tothe light-emitting diodes 142 a being the objects of transfer, and theUV-curable adhesive 148 at these locations is cured. Thereafter, thesecond temporary holding member 149 is released from the first temporaryholding member 143, upon which only the light-emitting diodes 142 abeing the objects of transfer are selectively separated, and aretransferred onto the second temporary holding member 149, as shown inFIG. 25.

After the selective separation, as shown in FIG. 26, a resin is appliedso as to cover the transferred light-emitting diodes 142, to form aresin layer 151. Further, as shown in FIG. 27, the thickness of theresin layer 151 is reduced by oxygen plasma or the like, and as shown inFIG. 28, via holes 152 are formed by irradiation with laser at positionscorresponding to the light-emitting diodes 142. For formation of the viaholes 152, there can be used excimer laser, higher harmonic YAG laser,carbon dioxide gas laser, and the like. At this time, the via holes 152are formed by opening holes with a diameter of about 3 to 7 μm, forexample.

Next, anode side electrode pads 153 to be connected to the p-electrodesof the light-emitting diodes 142 through the via holes 152 are provided.The anode side electrode pads 153 are formed of, for example, Ni/Pt/Au.FIG. 29 shows the condition where the light-emitting diodes 142 havebeen transferred onto the second temporary holding member 149, the viaholes 152 on the side of the anode electrodes (p-electrodes) have beenformed, and then the anode side electrode pads 153 have been formed.

After the anode side electrode pads 153 are formed, transfer onto athird temporary holding member 154 is conducted, for formation ofcathode side electrodes on the opposite side. The third temporaryholding member 154 also is formed, for example, of quartz glass. At thetime of transfer, as shown in FIG. 30, an adhesive 155 is applied to thelight-emitting diodes 142 provided with the anode side electrode pads153 and to the resin layer 151, and the third temporary holding member154 is adhered thereonto. In this condition, laser is radiated from theback side of the second temporary holding member 149, upon which releasedue to laser ablation occurs at the interface between the secondtemporary holding member 149 formed of quartz glass and the releaselayer 150 formed of polyimide on the second temporary holding member149. The light-emitting diodes 142 and the resin layer 151, which areformed on the release layer 150 are transferred onto the third temporaryholding member 154. FIG. 31 shows the condition where the secondtemporary holding member 149 has been separated.

At the time of forming the cathode side electrodes, after theabove-mentioned transfer step, an O₂ plasma processing shown in FIG. 32is conducted to remove the release layer 150 and excess portions of theresin layer 151, thereby exposing a contact semiconductor layer(n-electrodes) of the light-emitting diodes 142. In the condition wherethe light-emitting diodes 142 are held by the adhesive layer 155 on thetemporary holding member 154, the back side of the light-emitting diodes142 is the n-electrode side (cathode electrode side); when electrodepads 156 are provided as shown in FIG. 33, the electrode pads 156 areelectrically connected to the back side of the light-emitting diodes142. The electrode pad on the cathode side at this time can be, forexample, about 60 μm square. As the electrode pads 156, there may beused transparent electrodes (ITO, ZnO based) or a material such asTi/Al/Pt/Au. In the case of the transparent electrodes, emission oflight would not be blocked even if the back side of the light-emittingdiodes 142 is largely covered with the transparent electrodes, so thatpatterning accuracy may be rough, large electrodes can be formed, andthe patterning process becomes easy.

Next, the light-emitting diodes 142 fixed with the resin layer 151 andthe adhesive 155 are individually diced, into the state of theabove-mentioned resin-molded chips. The dicing may be performed, forexample, by laser dicing. FIG. 34 shows a dicing step by laser dicing.The laser dicing is conducted by irradiation with a laser line beam,whereby the resin layer 151 and the adhesive 155 are cut until the thirdtemporary holding member 154 is exposed. By the laser dicing, thelight-emitting diodes 142 are diced as the resin-molded chips having apredetermined size and are transported to an actual mounting step, whichwill be described later.

In the actual mounting step, the light-emitting diodes 142 (resin-moldedchips) are released from the third temporary holding member 154 by acombination of a mechanical means (suction of the devices by vacuumsuction) and laser ablation. FIG. 35 illustrates the condition where thelight-emitting diodes 142 arranged on the third temporary holding member154 are picked up by a suction equipment 157. Suction holes 158 at thistime are opened in a matrix form with the pixel pitch of the imagedisplay system, and a multiplicity of the light-emitting diodes 142 canbe picked up by suction at a stroke. For example, the diameter of theopenings is about 100 μm, the pitch of the matrix is about 600 μm, andabout 300 pieces are picked up by suction at a stroke. At this time, themember of the suction holes 158 is produced by Ni electroplating, or ametallic sheet of stainless steel (SUS), or the like provided with holesby etching. A suction chamber 159 is provided at the depth of thesuction holes 158, and the negative pressure in the suction chamber 159is controlled, whereby the light-emitting diodes 142 can be picked up bysuction. At this stage, the light-emitting diodes 142 are covered withthe resin layer 151, and the upper surface thereof is roughlyplanarized. Therefore, selective suction by the suction equipment 157can be carried out easily.

At the time of releasing the light-emitting diodes 142, pick up bysuction of the devices by the suction equipment 157 is combined with therelease of the resin-molded chips by laser ablation, whereby thereleasing causes to proceed smoothly. The laser ablation is conducted byradiating the laser from the back side of the third temporary holdingmember 154. By the laser ablation, release is generated at the interfacebetween the third temporary holding member 154 and the adhesive 155.

FIG. 36 illustrates the transfer of the light-emitting diodes 142 onto asecond substrate 161. The second substrate 161 is a wiring substrateprovided with a wiring layer 162, and at the time of fitting thelight-emitting diodes 142 thereto, an adhesive layer 163 ispreliminarily applied to the second substrate 161. The adhesive layer163 beneath the light-emitting diodes 142 is cured, whereby thelight-emitting diodes 142 can be arranged in the state of being fixed tothe second substrate 161. At the time of the fitting, the suctionchamber 159 of the suction equipment 157 is in a high pressurecondition, so that the connection between the suction equipment 157 andthe light-emitting diodes 142 by suction is released. The adhesive layer163 can be formed of a UV-curable type adhesive, a thermosettingadhesive, a thermoplastic adhesive, or the like. The positions ofarrangement of the light-emitting diodes 142 on the second substrate 161is spaced wider apart than in the arrangement on the first temporaryholding member 154. The energy for curing the resin constituting theadhesive layer 163 is supplied from the back side of the secondsubstrate 161. The adhesive layer 163 only at locations beneath thelight-emitting diodes 142 is cured by a UV irradiation equipment in thecase of the UV-curable type adhesive, and by infrared ray heating in thecase of the thermosetting adhesive. In the case of the thermoplasticadhesive, the adhesive is melted by irradiation with infrared rays orlaser, and adhesion is achieved.

FIG. 37 shows a process of arranging light-emitting diodes 164 for othercolor on the second substrate 161. When the suction equipment 157 shownin FIG. 35 is used as it is and mounting is conducted by shifting themounting positions on the second substrate 161 to the other colorpositions, it is possible to form pixels constituting of a plurality ofcolors while maintaining the pixel pitch to be constant. Here, thelight-emitting diodes 142 and the light-emitting diodes 164 may notnecessarily have the same shape. In FIG. 37, the light-emitting diodes164 for red color have a structure lacking in the hexagonal base pyramidshaped GaN layer and are different from the light-emitting diodes 142 inshape. At this stage, the light-emitting diodes 142 and 164 have alreadybeen covered with the resin layer 151 and the adhesive 155 to be theresin-molded chips, so that they can be dealt with in the same mannernotwithstanding the difference in device structure.

Next, as shown in FIG. 38, an insulating layer 165 is provided coveringthe resin-molded chips containing the light-emitting diodes 142, 164. Asthe insulating layer 165, there can be used a transparent epoxyadhesive, a UV-curable type adhesive, polyimide, and the like. After theformation of the insulating layer 165, a wiring forming step isconducted. FIG. 39 illustrates the wiring forming step. The figure showsthe condition where the insulating layer 165 is provided with openingportions 166, 167, 168, 169, 170, and 171, and wirings 172, 173, and 174for connection between the electrode pads for anodes and cathodes of thelight-emitting diodes 142, 164 and a wiring layer 162 on the secondsubstrate 161. The opening portions, namely, via holes formed at thistime can be large because the areas of the electrode pads for thelight-emitting diodes 142, 164 are large, and the positional accuracy ofthe via holes can be rougher as compared with the via holes that areformed directly in the light-emitting diodes. For example, via holeswith a diameter of about 20 μm can be formed, for the electrode padshaving a size of about 60 μm square. As for the depth of the via holes,there are three kinds of depth, for connection with the wiringsubstrate, for connection with the anode electrode, and for connectionwith the cathode electrode. Therefore, optimum depths are opened bycontrolling the pulse number of laser.

Thereafter, as shown in FIG. 40, a protective layer 175 is provided, anda black mask 176 is formed, to complete the panel of the image displaysystem. The protective layer 175 at this time is the same as theinsulating layer 165 shown in FIG. 37. Materials such as a transparentepoxy resin can be used. The protective layer 175 is heated and cured,to wholly cover the wirings. Thereafter, a driver IC is connected withthe wiring at an end portion of the panel, whereby a driving panel ismanufactured.

In the light-emitting device arranging method as described above, at thetime when the light-emitting diodes 142 are held on the temporaryholding member 149, 154, the interval between the devices is alreadyenlarged, and the electrode pads 153, 156 with a comparatively largesize can be provided by utilizing the enlarged spacing. Since the wiringis conducted by utilizing the electrode pads 153, 156 having thecomparatively large size, wiring can be easily carried out even in thecase where the final system size is conspicuously large as compared withthe device size. In addition, in the light-emitting device arrangingmethod in this example, the surroundings of the light-emitting diodes142 are covered with the resin layer 151, and the planarization makes itpossible to form the electrode pads 153, 156 with high accuracy.Besides, the electrode pads 153, 156 can be extended over a wider regionas compared with the device, and, in the case of performing the transferin the subsequent second transfer step by a suction jig, easy treatingof the devices is promised.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claims.

1. A method of producing an electronic part, comprising steps ofepitaxially growing a semiconductor crystal layer on a seed crystalsubstrate, embedding said semiconductor crystal layer into an insulatingmaterial and removing said seed crystal substrate, forming an electrodeconnected to a surface on one side of said semiconductor crystal layer,transferring said semiconductor crystal layer embedded in saidinsulating material onto a support substrate, forming an electrodeconnected to a surface on an opposite side of said semiconductor crystallayer, and forming lead-out electrodes connected to said electrodes.